One type of mop that has found commercial success is in the marketplace is a mop having an attached wringer cup, like the one disclosed in U.S. Pat. No. 5,060,338. Other examples may be found in U.S. Pat. Nos. 1,709,622; 3,364,512; 3,946,457; and 4,809,287; and German published patent Application No. DE 3607121 A1.
The wringer cups used on these kinds of mops often have grooves or ribs on the inside. When the cone-shaped wringer cup is pushed down over the mop fibers, the ribs help to squeeze water out of the mop fibers. The wringing is not always completely effective, however. Some of the water that has been squeezed out of the mop fibers can sometimes reenter the fibers before draining completely out of the wringer cup.